Modular electronic device

ABSTRACT

A modular electronic device is provided in a tubular form having a male bayonet connector at one end and a female bayonet connector at the other. A power and communications bus interconnects the connectors. An electronic circuit is located within the device in communication with the bus. Modular devices including an electronic timer, a printer module and a digital camera are provided. A number of the devices can be connected end-to-end to share different functionalities by means of the bus.

CROSS REFERENCES TO RELATED APPLICATIONS

The present application is a continuation of U.S. application Ser. No.10/636,275 filed on Aug. 8, 2003, now issued as U.S. Pat. No. 7,086,644,which is a divisional of U.S. application Ser. No. 09/575,137 filed onMay 23, 2000, now issued as Pat. No. 6,903,766.

FIELD OF THE INVENTION

The invention relates to a timer module useful in a digital imagingsystem. It is useful for controlling image capture by a digital imagesensor or camera. The timer module finds particular application in acompact printer system able to print full-color, business card sizedocuments from a device about the size of a pen.

Reference may be had to co-pending applications claiming priority fromAustralian Provisional Patent Application number PQ0560 dated 25 May1999. The co-pending applications describe related modules and methodsfor implementing the compact printer system. The co-pending applicationsare as follows:

USSN or Patent Number Title 6,924,907 Compact Color Printer Module6,712,452 Modular Compact Printer System 6,416,160 Nozzle CappingMechanism 6,238,043 Ink Cartridge for Compact Printer System 6,958,826Controller for Printer Module 6,812,972 Camera Module for CompactPrinter System 09/575,157 Image Processor for Camera Module 6,553,459Memory Module for Compact Printer System 6,967,741 Effects Module forCompact Printer System 6,956,669 Effects Processor for Effects Module6,804026 Color Conversion Method for Compact Printer System 09/575,120Method and Apparatus of Dithering 6,975,429 Method and Apparatus ofImage Conversion

BACKGROUND OF THE INVENTION

Microelectronic manufacturing techniques have led to the miniaturizationof numerous devices. Mobile phones, personal digital assistant devices,and digital cameras are very common examples of the miniaturizationtrend.

One device that has not seen the advantage of microelectronicmanufacturing techniques is the printer. Commercially available printersare large compared to many of the devices they could support. Forinstance, it is impractical to carry a color printer for the purpose ofinstantly printing photographs taken with known compact digital cameras.

A compact printhead has been described in co-pending United StatesPatent Applications filed simultaneously to the present application andhereby incorporated by cross reference:

USSN or Patent Number Title 7,018,016 Fluidic seal for an ink jet nozzleassembly 6,428,133 Ink jet printhead having a moving nozzle with anexternally arranged actuator 6,526,658 Method of manufacture of an inkjet printhead having a moving nozzle with an externally arrangedactuator 6,328,417 Ink jet printhead nozzle array 6,390,591 Nozzle guardfor an ink jet printhead

Some cameras have self-timers that allow a user time to move into framebefore a photo is taken. Self-timers are only useful for capturing asingle image. Some cameras also have the facility for taking multipleframes but this generally requires the user to maintain pressure on a‘take’ button. In any event, the timers are built in to the camera andhave fixed functionality.

SUMMARY OF THE INVENTION

In one form, the invention resides in a timer module comprising:

-   a body;-   control means within said body that automates the capture of    multiple images by a camera module, the capture of each image being    separated by a specific time interval;-   at least one connection means incorporated in said body for    connecting said timer module to a bus providing power and data    between said timer module and said camera module.

In a further form the invention resides in a timer module for a compactprinter system comprising:

-   a body;-   control means within said body that automates the capture of    multiple images by a connected camera module, the capture of each    image being separated by a specific time interval;-   at least one connection means incorporated in said body for    connecting said effects module to a bus providing power and data    between said effects module and said camera module.

In a still further form the invention resides in a method of automatingthe capture of multiple images by a camera module in a compact printersystem comprising the steps of:

-   setting a specific time interval between said capture of said    images,-   setting an initial image number on a connected memory module,-   starting said image capture process.

Further features of the invention will be evident from the followingdescription.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to assist with describing preferred embodiments of theinvention, reference will be made to the following figures in which:

FIG. 1 is a printer module;

FIG. 2 is a camera module;

FIG. 3 is a memory module;

FIG. 4 is a communication module;

FIG. 5 is a flash module;

FIG. 6 is a timer module;

FIG. 7 is a laser module;

FIG. 8 is an effects module;

FIG. 9 is a characters module;

FIG. 10 is an adaptor module;

FIG. 11 is a pen module;

FIG. 12 is a dispenser module;

FIG. 13 is a first compact printer configuration;

FIG. 14 is a second compact printer configuration;

FIG. 15 is a third compact printer configuration;

FIG. 16 is a fourth compact printer configuration;

FIG. 17 is a perspective view of the timer module;

FIG. 18 is an exploded view of the timer module; and

FIG. 19 is a block schematic diagram of a processor for the timermodule.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The invention is described in terms of the application to a compactprinter system. It will be understood that the invention is not limitedto this particular application but rather can be employed with anydigital imaging system. Nonetheless, the compact printer system providesa convenient environment in which to describe the details of the timermodule invention.

Referring to FIGS. 1 to 12, there are shown various modules thattogether form a compact printer system. Individual modules can beattached and detached from the compact printer configuration to allow auser-definable solution to business-card sized printing. Images can alsobe transferred from one compact printer to another without the use of asecondary computer system. Modules have a minimal user-interface toallow straightforward interaction.

A compact printer system configuration consists of a number of compactprinter modules connected together. Each compact printer module has afunction that contributes to the overall functionality of the particularcompact printer configuration. Each compact printer module is typicallyshaped like part of a pen, physically connecting with other compactprinter modules to form the complete pen-shaped device. The length ofthe compact printer device depends on the number and type of compactprinter modules connected. The functionality of a compact printerconfiguration depends on the compact printer modules in the givenconfiguration.

The compact printer modules connect both physically and logically. Thephysical connection allows modules to be connected in any order, and thelogical connection is taken care of by the compact printer Serial Bus—abus that provides power, allows the modules to self configure andprovides for the transfer of data.

In terms of physical connection, most compact printer modules consist ofa central body, a male connector at one end, and a female connector atthe other. Since most modules have both a male and female connector, themodules can typically be connected in any order. Certain modules onlyhave a male or a female connector, but this is determined by thefunction of the module. Adaptor modules allow these single-connectormodules to be connected at either end of a given compact-printerconfiguration.

A four wire physical connection between all the compact printer modulesprovides the logical connection between them in the form of the compactprinter Serial Bus. The compact printer Serial Bus provides power toeach module, and provides the means by which data is transferred betweenmodules. Importantly, the compact printer Serial Bus and accompanyingprotocol provides the means by which the compact printer systemauto-configures, reducing the user-interface burden on the end-user.

Compact printer modules can be grouped into three types:

-   -   image processing modules including a Printer Module (FIG. 1), a        Camera Module (FIG. 2), and a Memory Module (FIG. 3). Image        processing modules are primarily what sets the compact printer        system apart from other pen-like devices. Image processing        modules capture, print, store or manipulate photographic images;    -   housekeeping modules including an Adapter Module (FIG. 10), an        Effects Module (FIG. 8), a Communications Module (FIG. 4), and a        Timer Module (FIG. 6). Housekeeping modules provide services to        other modules or extended functionality to other modules; and    -   isolated modules including a Pen Module (FIG. 11) and a Laser        Module (FIG. 7). Isolated modules are those that attach to the        compact printer system but are completely independent of any        other module. They do not necessarily require power, and may        even provide their own power. Isolated Modules are defined        because the functionality they provide is typically incorporated        into other pen-like devices.

Although housekeeping modules and isolated modules are useful componentsin a compact printer system, they are extras in a system dedicated toimage processing and photographic manipulation. Life size (1:1)illustrations of the compact printer modules are shown in FIGS. 1 to 12,and example configurations produced by connecting various modulestogether are shown in FIGS. 13 to 16.

FIG. 1 shows a printer module that incorporates a compact printheaddescribed in co-pending United States Patent Applications listed in theBackground section of this application, incorporated herewith byreference, and referred to herewith as a Memjet printhead. The Memjetprinthead is a drop-on-demand 1600 dpi inkjet printer that producesbi-level dots in up to 4 colors to produce a printed page of aparticular width. Since the printhead prints dots at 1600 dpi, each dotis approximately 22.5 μm in diameter, and spaced 15.875 μm apart.Because the printing is bi-level, the input image should be dithered orerror-diffused for best results. Typically a Memjet printhead for aparticular application is page-width. This enables the printhead to bestationary and allows the paper to move past the printhead. A Memjetprinthead is composed of a number of identical ½ inch Memjet segments.

The printer module 10 comprises a body 11 housing the Memjet printhead.Power is supplied by a three volt battery housed in battery compartment12. The printhead is activated to commence printing when a business card(or similar sized printable media) is inserted into slot 13. Maleconnector 14 and female connector 15 facilitate connection of othermodules to the printer module 10.

FIG. 2 shows a camera module 20. The camera module provides apoint-and-shoot camera component to the compact printer system as ameans of capturing images. The camera module comprises a body 21 havinga female connector 22. A lens 23 directs an image to an image sensor andspecialized image processing chip within the camera 24. A conventionalview finder 25 is provided as well as a lens cap 26. An image iscaptured when the Take button 27 is pushed. Captured images aretransferred to the Printer Module 10 for subsequent printing,manipulation, or storage. The Camera Module also contains a self-timermode similar to that found on regular cameras.

FIG. 3 shows a Memory Module 30 comprising a body 31, LCD 32, IN button33, OUT button 34 and SELECT button 35. The Memory Module 30 is astandard module used for storing photographic images captured by theCamera 20. The memory module stores 48 images, each of which can beaccessed either at full resolution or at thumbnail resolution. Fullresolution provides read and write access to individual images, andthumbnail resolution provides read access to 16 images at once inthumbnail form.

The Memory. Module 30 attaches to other modules via a female connector36 or male connector 37. The male and female connectors allow the moduleto be connected at either end of a configuration. Power may be providedfrom the Printer Module 10 via the Serial Bus or from another source,such as a separate power module.

A Communications Module 40 is shown in FIG. 4. The communications module40 consists of a connector 41 and a cable 42 that terminates in anappropriate connector for a computer port, such as a USB port, RS232serial port or parallel port. The Communications Module 40 allows thecompact printer system to be connected to a computer. When so connected,images can be transferred between the computer and the various modulesof the compact printer system. The communications module allows capturedimages to be downloaded to the computer, and new images for printing tobe uploaded into the printer module 10 and the memory module 30.

A Flash Module 50 is shown in FIG. 5. The Flash Module 50 is used togenerate a flash with flash cell 51 when taking photographs with theCamera Module 20. The Flash Module attaches to other modules via femaleconnector 52 and male connector 53. It contains its own power source.The Flash Module is automatically selected by the Camera Module whenrequired. A simple switch allows the Flash Module to be explicitlyturned off to maximize battery life.

FIG. 6 shows a Timer Module 60 that is used to automate the taking ofmultiple photos with the Camera Module 20, each photo separated by aspecific time interval. The captured photos are stored in Memory Module30. Any flash requirements are handled by the Camera Module 20, and cantherefore be ignored by the Timer Module. The Timer Module 60 consistsof a body 61 housing an optional LCD 62, START/STOP button 63 and UNITSbutton 64. The LCD is optional since data from the Timer Module could besent on the serial bus to a specific display module. Nonetheless, it isconvenient to consider the LCD as part of the Timer Module.

A SELECT button 65 allows the user to select time units and the numberof units are set by UNITS button 64. The Timer Module 60 includes a maleconnector 66 and female connector 67. The Timer Module takes its powerfrom the Printer Module 10 via the Serial Bus or from another source,such as a separate power module.

A Laser Module 70 is shown in FIG. 7. The Laser Module 70 consists of abody 71 containing a conventional laser pointer operated by button 72.As the Laser Module is a terminal module it only has one connector,which in the example is a male connector 73. The Laser Module is anisolated module, in that it does not perform any image capture, storage,or processing. It exists as a functional addition to the compact printersystem. It is provided because laser pointer services are typicallyincorporated into other pen-like devices. The Laser Module contains itsown power supply and does not appear as a device on the Serial Bus.

The Effects Module shown in FIG. 8 is an image processing module. Itallows a user to select a number of effects and applies them to thecurrent image stored in the Printer Module 10 or memory module 30. Theeffects include borders, clip-art, captions, warps, color changes, andpainting styles. The Effects Module comprises a body 81 housing customelectronics and a LCD 82. A CHOOSE button 83 allows a user to choosebetween a number of different types of effects. A SELECT button 84allows the user to select one effect from the number of effects of thechosen type. Pressing the APPLY button 85 applies the effect to imagestored in the Printer Module 10. The Effects Module obtains power fromthe Serial Bus. Male connector 86 and female connector 87 allow theEffects Module to be connected to other compact printer system modules.

FIG. 9 shows a Character Module 90 that is a special type of EffectsModule (described above) that only contains character clip-art effectsof a given topic or genre. Examples include The Simpsons®, Star Wars®,Batman®, and Dilbert® as well as company specific modules for McDonalds®etc. As such it is an image processing module. It consists of a body 91housing custom electronics and a LCD 92. SELECT button 93 allows theuser to choose the effect that is to be applied with APPLY button 94.The Character Module obtains power from the Serial Bus through maleconnector 95 and female connector 96.

The Adaptor Module 100, shown in FIG. 10, is a female/female connectorthat allows connection between two modules that terminate in maleconnectors. A male/male connector (not shown) allows connection betweentwo modules that terminate in female connectors. The Adaptor Module is ahousekeeping module, in that it facilitates the use of other modules,and does not perform any specific processing of its own.

All “through” modules have a male connector at one end and a femaleconnector at the other end. The modules can therefore be chainedtogether, with each module connected at either end of the chain. Howeversome modules, such as the Laser Module 70, are terminating modules, andtherefore have either a male or female connector only. Suchsingle-connector modules can only be connected at one end of the chain.If two such modules are to be connected at the one time, an AdaptorModule 100 is required.

FIG. 11 shows a Pen Module 110 which is a pen in a module form. It is anisolated module in that it attaches to the compact printer system but iscompletely independent of any other module. It does not consume orrequire any power. The Pen Module is defined because it is a convenientextension of a pen shaped, pen sized device. It may also come with a cap111. The cap may be used to keep terminating connectors clean in thecase where the chain ends with a connector rather than a terminatingmodule.

To assist with accurately feeding a business card sized print media intoslot 13 of the printer module 10, a dispenser module 120 is provided asshown in FIG. 12. The dispenser module 120 comprises a body 121 defininga media storage volume 132 that holds a store of business card sizedprint media. The print media may be fed to a slot 13 in the PrinterModule via a media outlet 131. As shown in FIG. 13, a Printer Module 10locates into socket 122 on the dispenser module 120. A feed mechanism inthe form of a slider 123 allows individual business cards 130 to bemanually fed from the media storage volume 132, out through the mediaoutlet 131 and into the slot 13 in the Printer Module 10. When correctlyaligned, a card dispensed from the dispenser module by slider 123 entersslot 13 and is printed.

In the sense that a minimum configuration compact printer system must beable to print out photos, a minimum compact printer configurationcontains at least a Printer Module 10. The Printer Module holds a singlephotographic image that can be printed out via its Memjet printer. Italso contains the 3V battery required to power the compact printersystem.

In this minimum configuration, the user is only able to print outphotos. Each time a user inserts a business card 130 into the slot inthe Printer Module, the image in the Printer Module is printed onto thecard. The same image is printed each time a business card is insertedinto the printer. In this minimum configuration there is no way for auser to change the image that is printed. The dispenser module 120 canbe used to feed cards 130 into the Printer Module with a minimum offuss, as shown in FIG. 13.

By connecting a Camera Module 20 to the minimum configuration compactprinter system the user now has an instant printing digital camera in apen, as shown in FIG. 14. The Camera Module 20 provides the mechanismfor capturing images and the Printer Module 10 provides the mechanismfor printing them out. The battery in the Printer Module provides powerfor both the camera and the printer.

When the user presses the “Take” button 27 on the Camera Module 20, theimage is captured by the camera 24 and transferred to the Printer Module10. Each time a business card is inserted into the printer the capturedimage is printed out. If the user presses “Take” on the Camera Moduleagain, the old image in the Printer Module is replaced by the new image.

If the Camera Module is subsequently detached from the compact printersystem, the captured image remains in the Printer Module, and can beprinted out as many times as desired. The Camera Module is simply thereto capture images to be placed in the Printer Module.

FIG. 15 shows a further configuration in which a Memory Module 30 isconnected to the configuration of FIG. 14. In the embodiment of FIG. 15,the user has the ability to transfer images between the Printer Module10 and a storage area contained in the Memory Module 30. The userselects the image number on the Memory Module, and then either sendsthat image to the Printer Module (replacing whatever image was alreadystored there), or brings the current image from the Printer Module tothe specified image number in the Memory Module. The Memory Module alsoprovides a way of sending sets of thumbnail images to the PrinterModule.

Multiple Memory Modules can be included in a given system, extending thenumber of images that can be stored. A given Memory Module can bedisconnected from one compact printer system and connected to anotherfor subsequent image printing.

With the Camera Module 20 attached to a Memory Module/Printer Modulecompact printer system, as shown in FIG. 15, the user can “Take” animage with the Camera Module, then transfer it to the specified imagenumber in the Memory Module. The captured images can then be printed outin any order.

By connecting a Communications Module 40 to the minimum configurationcompact printer system, the user gains the ability to transfer imagesbetween a PC and the compact printer system. FIG. 16 shows theconfiguration of FIG. 15 with the addition of a Communications Module40. The Communications Module makes the Printer Module 10 and any MemoryModules 30 visible to an external computer system. This allows thedownload or uploading of images. The communications module also allowscomputer control of any connected compact printer modules, such as theCamera Module 20.

Each module is visible on the Serial Bus. Each module is selfidentifying and self-configuring using standard USB protocols. Apartfrom the standard protocol functions (including identification), thereare a number of functions to which each module is also capable ofresponding. These are outlined in Table 1. Each module also has a numberof module-specific functions. These commends allow the modules to becontrolled by an external device, such as a personal computer, and byother modules.

TABLE 1 Basic Module Functions Name Description GetImageCounts( )Returns two counts - the number of images that can be read from themodule, and the number of images that can be written to the module. Thisallows read only, write only, and virtual read only images.GetCurrentImageNumber If the module has a setting for the image number,this call returns the current image number. GetImageAccessMethodsReturns two sets of 8 access bits. The first set represents the readaccess bits, and the second set represents the write access bits. SeeTable 2 for an interpretation of the bits. GetImage(N, Mode) Returnsimage number N using the specified 8-bit access mode. See Table 3 for aninterpretation of the access mode bits. StoreImage(N, Mode) Stores animage at address N using the specified 8-bit access mode. See Table 3for an interpretation of the access mode bits. TransferImage(N1, Mode,Transfers the image at address N1 using the specified Dest, N2) 8-bitaccess mode to the image at address N2 at the serial device with idDest. See Table 3 for an interpretation of the access mode bits.

The 8-bit mode returned by GetImageAccessMethods is interpreted asfollows:

TABLE 2 8-bit return code from GetImageAccessMethods Bit Interpretation0 Access 850 × 534 permitted 1 Access 534 × 850 permitted 2 InterleavedL*a*b* permitted 3 Planar L*, a*, b* permitted 4-7 Reserved, and 0

The 8-bit mode used for image read and write access via GetImage,StoreImage and TransferImage is interpreted as follows:

TABLE 3 8-bit code used for read & write access Bit Interpretation 0Orientation: 0 = 850 × 534, 1 = 534 × 850 1 0 = interleaved, 1 = planar2-3 Color plane (valid only when bit 1 = planar) 00 = L*, 01 = a*, 10 =b*, 11 = reserved 4-7 Reserved, and 0

In some situations, certain modules may be configured without theprinter module. For example, it may be convenient to configure a cameramodule 20 and a memory module 30 for capturing and storing images forlater printing by the printer module 10. The timer module 60 and theflash module 50 may be added to the camera module 20 and memory module30 to produce a digital camera having many of the features of aconventional camera. Additional memory modules can easily be added toprovide virtually unlimited memory storage.

The above commands allow images to be transferred to and from themodules without going through the printer module. For example, theMemory Module 30 can act under control of the Timer Module 60 totransfer a captured image from the Camera Module 20 to the Memory Module30 using the TransferImage command. The Camera Module 20 will have amodule specific ‘capture’ command for capturing an image.

In the general case, the Printer Module holds the “current” image, andthe other modules function with respect to this central repository ofthe current image. The Printer Module is therefore the central locationfor image interchange in the compact printer system, and the PrinterModule provides a service to other modules as specified by userinteraction.

A given module may act as an image source. It therefore has the abilityto transfer an image to the Printer Module. A different module may actas an image store. It therefore has the ability to read the image fromthe Printer Module. Some modules act as both image store and imagesource. These modules can both read images from and write images to thePrinter Module's current image.

The standard image type has a single conceptual definition. The imagedefinition is derived from the physical attributes of the printhead usedin the Printer Module. The printhead is 2 inches wide and prints at 1600dpi in cyan, magenta and yellow bi-level dots. Consequently a printedimage from the compact printer system is 3200 bi-level dots wide.

The compact printer system prints on business card sized pages (85 mm×55mm). Since the printhead is 2 inches wide, the business cards areprinted such that 1 line of dots is 2 inches. 2 inches is 50.8 mm,leaving a 2 mm edge on a standard business-card sized page. The lengthof the image is derived from the same card size with a 2 mm edge.Consequently the printed image length is 81 mm, which equals 5100 1600dpi dots. The printed area of a page is therefore 81 mm×51 mm, or5100×3200 dots.

To obtain an integral contone to bi-level ratio a contone resolution of267 ppi (pixels per inch) is chosen. This yields a contone CMY page sizeof 850×534, and a contone to bi-level ratio of 1:6 in each dimension.This ratio of 1:6 provides no perceived loss of quality since the outputimage is bi-level.

The printhead prints dots in cyan, magenta, and yellow ink. The finaloutput to the printed page must therefore be in the gamut of theprinthead and take the attributes of the inks into account. It would atfirst seem reasonable to use the CMY color space to represent images.However, the printer's CMY color space does not have a linear response.This is definitely true of pigmented inks, and partially true fordye-based inks. The individual color profile of a particular device(input and output) can vary considerably. Image capture devices (such asdigital cameras) typically work in RGB (red green blue) color space, andeach sensor will have its own color response characteristics.

Consequently, to allow for accurate conversion, as well as to allow forfuture image sensors, inks, and printers, the CIE L*a*b* color model[CIE, 1986, CIE 15.2 Colorimetry: Technical Report (2^(nd) Edition),Commission Internationale De l'Eclairage] is used for the compactprinter system. L*a*b* is well defined, perceptually linear, and is asuperset of other traditional color spaces (such as CMY, RGB, and HSV).

The Printer Module must therefore be capable of converting L*a*b* imagesto the particular peculiarities of its CMY color space. However, sincethe compact printer system allows for connectivity to PCs, it is quitereasonable to also allow highly accurate color matching between screenand printer to be performed on the PC. However the printer driver or PCprogram must output L*a*b*.

Each pixel of a compact printer image is therefore represented by 24bits: 8 bits each of L*, a*, and b*. The total image size is therefore1,361,700 bytes (850×534×3).

Each image processing module is able to access the image stored in thePrinter Module. The access is either to read the image from the PrinterModule, or to write a new image to the Printer Module.

The communications protocol for image access to the Printer Moduleprovides a choice of internal image organization. Images can be accessedeither as 850×534 or as 534×850. They can also be accessed ininterleaved or planar format. When accessed as interleaved, each pixelin the image is read or written as 24 bits: 8 bits each of L*, a*, b*.When accessed as planar, each of the color planes can be read or writtenindependently. The entire image of L* pixels, a* pixels or b* pixels canbe read or written at a time.

The Timer Module 60 is used to automate the capture of multiple imageswith a Camera Module 20, the capture of each image being separated by aspecific time interval. The captured images are stored in an on-lineMemory Module 30. Any flash requirements are handled by the CameraModule 20, and can therefore be ignored by the Timer Module.

FIG. 17 shows a magnified perspective view of the Timer Module 60, aspreviously described with reference to FIG. 6. The optional LCD 62provides visual feedback. It contains a 2-digit numerical display 68representing the number of time units between captured images. Threetime units are available: seconds, minutes, and hours, represented by s,m, and h LCD segments respectively. A multi-segment thermometer 69provides an animated countdown between image captures. As shown in FIG.17, the LCD 62 is showing all segments active.

FIG. 18 is an exploded perspective view of the Timer Module 60. The LCD62 is mounted on a flexible printed circuit board (PCB) 300. Withreference to FIG. 19, also formed on the PCB 300 is a simplemicrocontroller 351 which is suitably an application specific integratedcircuit (ASIC) 350.

In reference to FIG. 18, the UNITS button 64 is a double button andoperates in the manner of a known rocker switch to increment ordecrement the number of time units. Selections made using the UNITSbutton 64 are communicated to the PCB 300 via contact 301.

The flexible PCB 300 is mounted on a support 303 of chassis molding 302.In the preferred embodiment the PCB 300 is mounted such that the LCD 62lies substantially parallel with a front face 304 of the support 303.The flexible PCB 300 passes over the support such that the ASIC 350 liessubstantially parallel with a back face 305 of the support 303. Theflexible PCB 300 passes under the ASIC 350 and extends away from thebase 306 of the chassis molding 302.

The contact 301 conforms to a curved edge of the support 303 allowingthe base of UNITS button 64 to lie substantially parallel with a sideface 310 of the support.

The male bayonet connector 66 comprises a cap molding 307, a latch strip308 and a plurality of contact strips 309. The upper end of the capmolding is essentially dome-shaped and comprises two holes 311positioned diametrically opposite each other. The holes 311 arepositioned and shaped to receive the folded ends 312 of latch strip 308.

The lower end of the cap molding 307 comprises an elongated section 313that is shaped to carry contact strips 309. The contact strips extendfrom the upper end of the cap molding, where they form part of the maleconnector 66, to the bottom of the elongated section 313. The bottom ofthe elongated section fits into a recess 314 in the base 306 of thechassis molding such that the contact strips 309 form part of the femalebayonet connector 67.

Raised portions 315 of the contact strips 309 fit into an aperture 316in the elongated section 313 of the cap molding. Contacts on theflexible PCB 300 mate with the raised portions 315 to make contact withthe Serial Bus.

The START/STOP button 63 and the SELECT button 65 are incorporated in amolding 317. A contact in the base of the molding for each buttonconnects with the PCB 300 when one or other of the buttons is pressed.

The internal components of the Timer Module 60 are contained within ametal extrusion 318 that comprises a plurality of apertures. It is clearfrom FIG. 18 the manner in which the buttons 63, 64 and 65, and the maleconnector 66 protrude from the extrusion through the associatedapertures to perform their function.

A fascia molding 319 clips into the aperture 320 and provides aprotective cover for the LCD 62.

The Timer Module 60 connects to a compact printer configuration via themale connector 66 or the female connector 67. Either the male or thefemale bayonet connector joins the Timer Module to the Serial Bus viacontact strips 309. Power is provided to the Timer-Module from thePrinter Module 10 via the Serial Bus or from a separate power module.

Alternatively, the Timer Module 60 may be connected to a compact printerconfiguration via both the male and female bayonet connectors. Anexample of this principle is shown in FIG. 16 where the Memory Module 30is connected to the Printer Module 10 via its male connector and isconnected to the Communications Module 40 via its female bayonetconnector.

The Timer Module 60 must be used in conjunction with a Camera Module 20and at least one Memory Module 30. The first stage of Timer Module useis therefore to construct a configuration containing at least theseModules. Power may be provided from a power module, a Printer Module 10or a personal computer through the communications module 40. However,the Modules may be connected in any order. The Modules are joinedtogether using the bayonet connectors as previously described.

The Timer Module queries all the modules in the system to locate thecamera module and any number of memory modules. A list is compiled ofavailable memory modules and ranges of available image numbers withinthose modules. The total number of available image storage locations Nis recorded. The timer then instructs the camera N times to captureimages and transfer the images to the memory module until all storagelocations are full. The timer waits an elapsed time between each imagecapture. The elapsed time is set by the user using the buttons orcommanded from an external source using the timer module command set.The Timer Module commands the transfer of the captured image from thecamera module to the memory module using the TransferImage commanddescribed above.

Once the START button 63 is pressed, the Timer Module 60 counts down thespecified time, and then instructs the Camera Module 20 to capture andtransfer an image to the appropriate Memory Module 30.

When only a single Memory Module is present in the configuration, afterthe START button 63 is pressed, the Timer Module continues to capture animage after every time interval has elapsed and transfer each capturedimage to the single Memory Module until that Memory Module is full.

When there are multiple Memory Modules in the configuration, the processis the same as for the single Memory Module, except that the MemoryModules are filled up one by one until all Memory Modules have beenfilled. The first Memory Module to be written to is the one physicallyclosest to the Camera Module 20, and the last Memory Module to bewritten to is the one physically furthest from the Camera Module.

Two tasks need to be accomplished before the Timer Module 60 can beactivated to begin a countdown. The duration of the time intervalbetween the capture of each image must be set and the initial imagenumber on the Memory Module(s) must be set. These tasks can be performedin any order.

The duration of the time interval between the capture of each image isset by selecting the time unit using the SELECT button 65 and thenselecting the number of those units using the UNITS button 64. Forexample, a time interval of 30 seconds can be accomplished by selectingthe seconds units, and then adjusting the number to 30. A time intervalof 15 minutes can be accomplished by selecting the minutes units andthen adjusting the number to 15. The Timer Unit maintains a context foreach unit so as to minimize the change required by the user.

Alternatively the duration can be set from a personal computer oranother module using the Timer Module command set.

The first image to be written to a specific Memory Module will bewritten to the current image number displayed on that Memory Module. Theimage number is then incremented. The image number is set by means ofthe SELECT button 35 on the Memory Module. Setting the initial imagenumber before the Timer Module is activated lets the user specify howmany images each Memory Module will capture. For example, setting a 48image Memory Module to 40 allows the capture of 9 images: images 40, 41,42, 43, 44, 45, 46, 47, and 48. Once the image count reaches 48 it stopsand no further images are written to that Memory Module. If multipleMemory Modules are present, the Memory Module next closest to the CameraModule will be written to.

Once the two preliminary tasks have been done, the Timer Module'sSTART/STOP button 63 can be pressed to start the Timer Module. Pressingthe START/STOP button 63 a second time stops the Timer Module. While theTimer Module is actively counting down, feedback is given in two ways.Firstly, the time unit LCD segment (s, m or h) flashes on and off (1second on, 1 second off) to let a user know the countdown is active.Secondly, a multi-segment thermometer 69 provides an animated countdownof the proportion of time elapsed until the next image capture time.

As mentioned above, the Timer Module contains an integrated circuit 350.The elements of the integrated circuit 350 are shown in FIG. 19. Theseelements include a simple microcontroller 351, a Serial Bus Interface352, a small scratch RAM 353 for storing timing instructions and a smallprogram memory 354. State information is limited to the current timeunit setting (seconds, minutes, hours), the number of time units (2-60seconds, 1-60 minutes, 1-96 hours), whether the timer is active (yes,no), the time until the next image capture (2-60 s, 1-60 m, 1-96 h), thecurrent Camera Module target, the current Memory Module target and thenext Memory Module image number. Instructions are limited to setting thetime units, setting the number of time units, starting and stopping thetimer.

Also included in the ASIC is a memory decoder 355 and parallel interface356 (that communicates with the LCD and various buttons). A Joint TestAction Group unit 357 may be included for self-test purposes. In somecircumstances a clock 358 and crystal oscillator 359 may be required.

The combination of the Memory Module 30 with a Camera Module 20constitutes a digital imaging system. This combination allows an imagecaptured by the Camera Module to be stored in the Memory Module. Theaddition of the Timer Module 60 allows multiple images to be capturedand stored automatically.

Throughout the specification the aim has been to describe the preferredembodiments of the invention without limiting the invention to any oneembodiment or specific collection of features. Persons skilled in therelevant art may realize variations from the specific embodiments thatwill nonetheless fall within the scope of the invention.

1. A modular electronic printing device including: a cylindrical outersleeve defining a number of external windows and housing a printhead,the sleeve further defining a media inlet and a media outlet; a firstconnector extending from a first end of said sleeve; a second connectorlocated at an opposing second end of said sleeve; a plurality of contactstrips disposed along the inside of the cylindrical outer sleeve withopposing ends respectively terminating at the first connector and thesecond connector; an electronic circuit located within the device andarranged to make electrical contact with medial portions of the contactstrips; a visual display mounted within one of said windows and coupledto the electronic circuit; and one or more switches mounted in othersaid windows and coupled to the electronic circuit.
 2. The modularelectronic device according to claim 1, including a member disposedbetween the electronic circuit and the contact strips, the memberincluding an aperture accommodating connections between the electroniccircuit and the contact strips.
 3. The modular electronic deviceaccording to claim 1, wherein the first connector comprises a malebayonet connector and the second connector comprises a female bayonetconnector.
 4. The modular electronic device according to claim 3,including a molding disposed between the electronic circuit and thecontact strips and continuous with the male bayonet connector and thefemale bayonet connector, the molding including an aperture receivingconnections between the electronic circuit and the contact strips. 5.The modular electronic device according to claim 4, wherein theelectronic circuit comprises a flexible printed circuit board.
 6. Themodular electronic device according to claim 5, wherein the flexibleprinted circuit board is located between the molding and a supportprojecting from the female bayonet connector.
 7. The modular electronicdevice according to claim 5, including an arrangement to lock theflexible printed circuit board fast with the male bayonet connector. 8.The modular electronic device according to claim 7 comprising anelectronic timer.